From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45052) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apyKT-00036P-Em for qemu-devel@nongnu.org; Tue, 12 Apr 2016 09:26:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1apyKP-0005WH-8z for qemu-devel@nongnu.org; Tue, 12 Apr 2016 09:26:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48030) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apyKO-0005WA-2E for qemu-devel@nongnu.org; Tue, 12 Apr 2016 09:26:01 -0400 From: Stefan Hajnoczi Date: Tue, 12 Apr 2016 14:25:33 +0100 Message-Id: <1460467534-29147-10-git-send-email-stefanha@redhat.com> In-Reply-To: <1460467534-29147-1-git-send-email-stefanha@redhat.com> References: <1460467534-29147-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PATCH v3 09/10] virtio: handle virtqueue_num_heads() errors List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" , Cornelia Huck , Fam Zheng , Stefan Hajnoczi If the avail ring index is bogus virtqueue_num_heads() must return -EINVAL. The only caller is virtqueue_get_avail_bytes(). Return saying no bytes are available when virtqueue_num_heads() fails. Signed-off-by: Stefan Hajnoczi --- hw/virtio/virtio.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 58599cf..4fe342a 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -323,9 +323,9 @@ static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) /* Check it isn't doing very strange things with descriptor numbers. */ if (num_heads > vq->vring.num) { - error_report("Guest moved used index from %u to %u", + virtio_error(vq->vdev, "Guest moved used index from %u to %u", idx, vq->shadow_avail_idx); - exit(1); + return -EINVAL; } /* On success, callers read a descriptor at vq->last_avail_idx. * Make sure descriptor read does not bypass avail index read. */ @@ -393,7 +393,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, idx = vq->last_avail_idx; total_bufs = in_total = out_total = 0; - while (virtqueue_num_heads(vq, idx)) { + while ((rc = virtqueue_num_heads(vq, idx)) > 0) { VirtIODevice *vdev = vq->vdev; unsigned int max, num_bufs, indirect = 0; VRingDesc desc; @@ -454,6 +454,11 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, else total_bufs++; } + + if (rc < 0) { + goto err; + } + done: if (in_bytes) { *in_bytes = in_total; -- 2.5.5